package io.rehuo.common.utils;

import java.util.Random;
import java.util.UUID;

public class CommonUtils {

    private static final char[] CODE_CHARS = {
            '0', '1', '2', '3', '4', '5', '6', '7', '8', '9'};
    private static final char[] CHARS = {
            '0', '1', '2', '3', '4', '5', '6', '7', '8', '9',
            'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n',
            'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z',
            'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N',
            'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z'};

    public static String uuid() {
        UUID uuid = UUID.randomUUID();
        String randomUUIDString = uuid.toString();
        return randomUUIDString;
    }

    public static String getRandomString(int length) {
        Random random = new Random();
        StringBuffer sb = new StringBuffer();

        for (int i = 0; i < length; ++i) {
            int number = random.nextInt(CODE_CHARS.length);
            sb.append(CODE_CHARS[number]);
        }

        return sb.toString();
    }

}
